Image signal encoding/decoding method and apparatus therefor

Abstract

An image decoding method is provided, which includes: generating a merge candidate list of a current block; specifying any one of a plurality of merge candidates included in the merge candidate list; on the basis of a first affine seed vector and a second affine seed vector of the specified merge candidate, inducing a first affine seed vector and a second affine seed vector of the current block; using the first affine seed vector and the second affine seed vector of the current block, inducing an affine vector regarding a sub-block in the current block; and on the basis of the affine vector, performing motion compensation prediction regarding the sub-block.

What is claimed is: 
     
         1 . A video decoding method comprising the steps of:
 parsing absolute value information for determining an absolute value of a residual coefficient from a bitstream when a non-zero flag indicates that the residual coefficient is non-zero; and   determining the absolute value of the residual coefficient based on the absolute value information,   wherein   the absolute value information comprises a residual coefficient comparison flag indicating whether the residual coefficient is greater than a first value,   a parity flag is further parsed from the bitstream only when the residual coefficient is greater than the first value,   a first adjusted remnant coefficient comparison flag indicating whether an adjusted remnant coefficient derived by bit-shifting the residual coefficient to the right by 1 is greater than a second value is further parsed when the residual coefficient is greater than the first value,   a second adjusted remnant coefficient comparison flag indicating whether the adjusted remnant coefficient is greater than a third value is further parsed when the adjusted remnant coefficient is greater than the second value, and   one or more adjusted remnant coefficient comparison flags indicating whether the adjusted remnant coefficient is greater than one or more values are further parsed when the adjusted remnant coefficient is greater than the third value.   
     
     
         2 . The method of  claim 1 , wherein
 a residual value information is further parsed when the adjusted remnant coefficient is greater than the second value, and   the residual value information includes a value obtained by subtracting the second value from the adjusted remnant coefficient.   
     
     
         3 . The method of  claim 1 , wherein the parity flag indicates whether the value of the residual coefficient is an even number or an odd number. 
     
     
         4 . A video encoding method comprising the steps of:
 encoding absolute value information for determining an absolute value of a residual coefficient when the residual coefficient is non-zero,   wherein   the absolute value information includes a residual coefficient comparison flag indicating whether the residual coefficient is greater than a first value,   a parity flag for the residual coefficient is further encoded only when the residual coefficient is greater than the first value,   a first adjusted remnant coefficient comparison flag indicating whether an adjusted remnant coefficient derived by bit-shifting the residual coefficient to the right by 1 is greater than a second value is further encoded when the residual coefficient is greater than the first value,   a second adjusted remnant coefficient comparison flag indicating whether the adjusted remnant coefficient is greater than a third value is further encoded when the adjusted remnant coefficient is greater than the second value, and   one or more adjusted remnant coefficient comparison flags indicating whether the adjusted remnant coefficient is greater than one or more values are further encoded when the adjusted remnant coefficient is greater than the third value.   
     
     
         5 . The method of  claim 4 , wherein
 residual value information is further encoded when the adjusted remnant coefficient is greater than the second value, and   the residual value information includes a value obtained by subtracting the second value from the adjusted remnant coefficient.   
     
     
         6 . The method of  claim 4 , wherein the parity flag indicates whether the value of the residual coefficient is an even number or an odd number. 
     
     
         7 . A non-transitory computer-readable storage medium, having a computer program and a bitstream stored thereon, wherein the computer program, when executed by a processor, enables the processor to perform a video encoding method to generate the bitstream, wherein the video encoding method comprises:
 encoding absolute value information for determining an absolute value of a residual coefficient when the residual coefficient is non-zero,   wherein   the absolute value information includes a residual coefficient comparison flag indicating whether the residual coefficient is greater than a first value,   a parity flag for the residual coefficient is further encoded only when the residual coefficient is greater than the first value,   a first adjusted remnant coefficient comparison flag indicating whether an adjusted remnant coefficient derived by bit-shifting the residual coefficient to the right by 1 is greater than a second value is further encoded when the residual coefficient is greater than the first value,   a second adjusted remnant coefficient comparison flag indicating whether the adjusted remnant coefficient is greater than a third value is further encoded when the adjusted remnant coefficient is greater than the second value, and   one or more adjusted remnant coefficient comparison flags indicating whether the adjusted remnant coefficient is greater than one or more values are further encoded when the adjusted remnant coefficient is greater than the third value.